Styling issues with Theia 1.31.1

Describe the problem

This is a follow-up task of #1655.

As noted in https://github.com/arduino/arduino-ide/issues/1655#issuecomment-1308516491, IDE2 styling contradicts the stylings dictated by the Theia framework.

This issue should be used to track styling issues so that our designers can provide instructions on how to handle them:

From https://github.com/arduino/arduino-ide/issues/1655#issuecomment-1308516491:

@91volt, Theia 1.31.0 comes with changes to have better accessibility support. Here and there the Theia styles contradict IDE2 styles. In this comment, I will attach screenshots depicting which UI parts are affected. (I will periodically update the comment with new findings if any.)

From https://github.com/arduino/arduino-ide/pull/1662#issuecomment-1330165727:

This contextual menu icon in the sketch control toolbar seems a little off to me:

I found that adding this CSS rule would fix it:
#arduino-open-sketch-control--toolbar {
    text-align: center;
}

To reproduce

See description

Expected behavior

All styling differences are adjusted or accepted

Arduino IDE version

https://github.com/arduino/arduino-ide/pull/1662

Operating system

macOS

Operating system version

12.5.1

Additional context

No response

Issue checklist

[X] I searched for previous reports in the issue tracker
[X] I verified the problem still occurs when using the latest nightly build
[X] My report contains all necessary details

arduino / arduino-ide

Styling issues with Theia 1.31.1 #1720